Method for the texturization of yarns, and the product thereof

ABSTRACT

A method and a device for texturing yarns, more particularly synthetic yarns, is disclosed, in which the false twist annular body is made of rubber having a hardness of 70 Shore and over. Advantageously, the yarn is heated, upstream of the false twist annular body, at a temperature well below the melting point of the material forming the yarn. Critical dimensions for the false twist annular body and for the distance therefrom of the tube on which the yarn is wound, are also specified. It is preferred that the yarn be drawn prior to reaching the false twist annular body.

United States Patent Faraci et a].

[ Mar. 19, 19745 [5 METHOD FOR THE TEXTURIZATION OF l/1962 Maier et a]57/157 TS YARNS, AND THE PRODUCT THEREOF 3,069,837 12/1962 Olson 57/157TS 3,093,955 6/1963 Cadario 57/34 HS Inventors: rg F us pp d both3,474,612 10/1969 Jenkins et al. 57/34 HS of Gozzana, Italy 73 Assignee:Bemberg s.p.A., Milan, Italy 'w Examinerlohn Petrakes Attorney, Agent,or Firm-Diner, Brown, Ramik & [22] Filed: Mar. 16, 1971 Holt [21] Appl.No.: 124,797

[57] ABSTRACT [30] Foreign Application Priority Data A method and adevice for texturing yarns, more par- Mar. 18, 1970 Italy 22137/70ticulafly Synthetic yarns, is disclosed, in which the false twistannular body is made of rubber having a [52] us L 57/140' 57 34 HS, 57157 TS hardness of 70 Shore and over. Advantageously, the 51 lm. c1.D02g 1/02 yarn is heated, upstream of the false twist annular 581 Fieldof Search 57/34 HS, 77.4, 157 TS, body, at a temperature well below themelting point of 1 57 4 R the material forming the yarn. Criticaldimensions for the false twist annular body and for the distance there-[56] References Cited from of the tube on which the yarn is wound, arealso UNITED STATES PATENTS specified. It is preferred that the yarn bedrawn prior to reaching the false twist annular body. 3,376,698 4/1968Whittaker et al 57/34 HS 3.029.591 4/1962 Scragg et a1. 57/77.4 X 6Claims, 1 Drawing Figure PA IENTEBm 1 9 mm 3.797; 220

INVENTOR CHURGID FQRQ I 6K GIUSE PPE GDDI m mmw ATTORNEYS METHOD FOR THETEXTURIZATION OF YARNS, AND THE PRODUCT THEREOF This invention relatesto a method for the production of a texturized yarn, in which a slidingyarn, while it forms a balloon, is wound around a spindle with the aidof a vertically ring and traveler which surrounds said spindle, in whichmethod the yarn is heated and, as it enters the balloon it rotates aboutits own longitudinal axis and slides against an annular false-twistingbody, so as to impart to the yarn a twist angle. The invention alsocomprises a device for performing the method and the yarn obtainedthereby.

A method as mentioned above is conventional. In the known method thefalse-twist annular body is also a heating means, so that it isdifficult to select an appropriate material for the interior surface ofthe annular false twist body, that is, the material on which the yarn isallowed to slide in the most regular possible manner. As a matter offact, a regular sliding of the yarn against said surface is necessary inorder that a uniform yarn, having a sufficient degree of false twist, ortexturization, may be obtained. Furthermore, in the known method, theannular false-twist body is positioned above the rotating spindle at arather long distance therefrom.

An object of the invention is to provide a method of the kind referredto above, which is not impaired by the defects enumerated hereinabove.The method according to the invention is characterized in that thesurface of the annular false-twist body is made of rubber or anothermaterial which has similar frictional properties.

According to a preferred embodiment, the inside diameter of the annularfalse-twist body varies between mms. greater than and30 mms. less thanthe outside diameter of the tube on which the treated yarn is wound,whereas the distance between the lower portion of the annularfalse-twist body and the upper portion of the tube is between 1 and 10mms. According to the invention it is preferred that the balloon tensionof the yarn is kept virtually constant. This can be obtained by varyingthe spindle speed according to a preselected program.

According to the invention, particularly favourable results are obtainedif the yarn is heated upstream of the annular false-twist body, forexample by a heated pin, a heated plate or a heated roller, which have atemperature lying in the range from C and 60C below the melting point ofthe thread, for example in the case of a polyamide yarn.

According to the invention, the method is advantageously performed ifthe yarn is drawn upstream of the annular false-twist body, the latterbeing preferably made of a rubber having a hardness of at least 70Shore.

A device for performing the method according to the invention comprisesyarn feeding means, yarn forwarding means, a ring spindle on which atube for winding the yarn is inserted, an annular false-twist bodyplaced above said ring spindle, and means for heating the yarn, and ischaracterized in that the surface of the annular false-twist body overwhich the yarn slides is of rubber, which more particularly has ahardness of at least 70 Shore, or is of a different material havingsimilar frictional properties.

According to a preferred embodiment of the device according to theinvention, a yarn-heating means is providedupstream of the annularfalse-twist body.

The invention will now be illustrated in more detail with reference tothe accompanying diagrammatigaldrawing.

A non texturized starting yarn 1, which is not drawn, is unthreaded froma spool 2 through a yarn guide 3 placed in front of the spool. The yarnis guided by a guiding roller 4 towards a driven feed roller 5 coupledwith a pressure roller 6. Subsequently, the yarn is drawn by a drivendrawing roller 7 with the aid of a separator roller 8, the surface speedof the drawing roller being adjusted so as to be a few times a multipleof that of the feed roller. Then the drawn yarn passes over a hot pin 9and enters the annular false-twist body 10 whose internal surface is ofa rubber having a hardness of at least 70 Shore, the body 10 having aheight of mms., and inside diameter of 28 mms., and an outside diameterof 48 mms. The yarn slides against the surface of the innercircumference of the false-twist body 10, which is arranged above thetube 11, about which the yarn is wound, at a distance ranging from 1 to10 mms. The diameter of the tube 11 is 50 mms. The tube 11 is insertedinto a driven twisting spindle 12. On the tube 11 the yarn is wound inthe form of a pack 13 by means of a vertically reciprocable ring andtraveler system 14 which causes the yarn to rotate and to build aballoon 15 between the ring 14 and the annular false-twist body 10. Theannular false-twist body is not rotated. However, with the aid of theannular false-twist body 10, a very high degree of false-twist can beimparted to the yarn, inasmuch as the diameter of the yarn is muchsmaller than the inside diameter of the annular false- !twistbody overwhich the yarn if forced to slide.

i By way of example, favourable results have been achieved with a6-filament polycaprolactam yarn having a count of 22 dtex., said yarnhaving been drawn at {a draw ratio of 2.65 and at a surface speed of thedrawi ta ler? o 400 me minute- Thedrawn yarn had the followingspecifications: Elongation at break 31.5% Tensile strength 420 gr/lOOdtex Shrinkage 7 l% Sensitivity to twist 209 revolutions/ cm.

, hank and, after one minute the total length (L taken by the hank isread on a dial placed behind the hank. The weight is removed and theshank is transferred during 45 minutes into an oven with air heated toC, whereafter the hank is removed from the oven and placed to beconditioned during 60 minutes in an atmosphere as conditioned to 22C andpercent rel. humidity. After that time, the hank is hung again to thehook and a weight of 0.002 grams/dtex is hung to the hank and the length(L taken by the hank is read after one minute.

Shrinkage is calculated with the formula r n 15f L .-1Q-.-. f 3 With theterm sensitivity to twist," it is intended herein to connote a measuretaken according to the following method. A section of horizontal yarn isaffixed at its two ends to two clamps, so as to have a yarn lengthcomprised between the two clamps of 50 cms. and a tension of the yarnequal to the weight of 1,000 meters of the yarn. A 2-gram weight is hungat the middle of the horizontal yarn length and the two clamps, whichcan slide on a horizontal plane, are approached until they contact oneanother. By so doing, the yarn forms a loop which is twisted over itselfa certain number of times, inasmuch as the yarn has a twisting moment.Once an equilibrium has been reached, a revolution counter indicates howmany revolutions are required to untwist the loop. This value, asreferred to the SO-cms. length of yarn expresses just the sensitivity totwist.

Variations are possible within the scope of the invention.

What is claimed is:

l. A method for the production of texturized yarn, in which a slidingyarn is wound, as it builds up a ballon, on a spindle with the aid of avertically reciprocable ring and traveler which surrounds said spindle,in which method the yarn is heated and as the heated yarn enters theballoon it is rotated about its longitudinal axis by sliding over theinner surface of a false-twist annular body, so as to impart a twistangle to the yarn, characterized in that the distance between the lowerportion of the annular false-twist body and the upper portion of thetube on which the yarn is being wound lies between 1 and 10 mms, and theinside diameter of the falsetwise annular body varies between 10 mms.greater than and 30 mms less than the outside diameter of the tube onwhich the yarn is being wound.

2. The method of claim 1 wherein the annular falsetwist body engages theyarn with a frictional surface formed of rubber-like material.

3. The method of claim 1 wherein the annular falsetwist body engages theyarn with a frictional surface formed of rubber-like material, having ahardness of at least Shore.

4. A method according to claim 1, characterized in that the yarn is apolyamide yarn and the temperature is comprised between 15C below, and60C below the melting point of the yarn.

5. A method according to claim 1, characterized in that the yarn isdrawn upstream of the false-twist annular body.

6. A yarn as produced according to the method as claimed in claim 1.

1. A method for the production of texturized yarn, in which a slidingyarn is wound, as it builds up a ballon, on a spindle with the aid of avertically reciprocable ring and traveler which surrounds said spindle,in which method the yarn is heated and as the heated yarn enters theballoon it is rotated about its longitudinal axis by sliding over theinner surface of a falsetwist annular body, so as to impart a twistangle to the yarn, characterized in that the distance between the lowerportion of the annular false-twist body and the upper portion of thetube on which the yarn is being wound lies between 1 and 10 mms, and theinside diameter of the false-twise annular body varies between 10 mms.greater than and 30 mms less than the outside diameter of the tube onwhich the yarn is being wound.
 2. The method of claim 1 wherein theannular false-twist body engages the yarn with a frictional surfaceformed of rubber-like material.
 3. The method of claim 1 wherein theannular false-twist body engages the yarn with a frictional surfaceformed of rubber-like material, having a hardness of at least 70 Shore.4. A method according to claim 1, characterized in that the yarn is apolyamide yarn and the temperature is comprised between 15*C below, and60*C below the melting point of the yarn.
 5. A method according to claim1, characterized in that the yarn is drawn upstream of the false-twistannular body.
 6. A yarn as produced according to the method as claimedin claim 1.